FAIMS

STUDY OBJECTIVES: Given the established racial disparities in both sleep health and dementia risk for African American populations, we assess cross-sectional and longitudinal associations of self-report sleep duration (SRSD) and daytime sleepiness with plasma amyloid beta (Aβ) and cognition in an African American (AA) cohort. METHODS: In a cognitively unimpaired sample drawn from the African Americans Fighting Alzheimer's in Midlife (AA-FAiM) study, data on SRSD, Epworth Sleepiness Scale, demographics, and cognitive performance were analyzed...

The proteome characterization of complex, deteriorated, or cross-linked protein mixtures as paired clinical FFPE or exosome samples isolated from low plasma volumes (250 µL) might be a challenge. In this work, we aimed at investigating the benefits of FAIMS technology coupled to the Orbitrap Exploris 480 mass spectrometer for the TMT quantitative proteomics analyses of these complex samples in comparison to the analysis of protein extracts from cells, frozen tissue, and exosomes isolated from large volume plasma samples (3 mL)...

Characterization of histone proteoforms with various post-translational modifications (PTMs) is critical for a better understanding of functions of histone proteoforms in epigenetic control of gene expression. Mass spectrometry (MS)-based top-down proteomics (TDP) is a valuable approach for delineating histone proteoforms because it can provide us with a bird's-eye view of histone proteoforms carrying diverse combinations of PTMs. Here, we present the first example of coupling capillary zone electrophoresis (CZE), ion mobility spectrometry (IMS), and MS for online multi-dimensional separations of histone proteoforms...

Sample multiplexing-based proteomic strategies rely on fractionation to improve proteome coverage. Tandem mass tag (TMT) experiments, for example, can currently accommodate up to 18 samples with proteins spanning several orders of magnitude, thus necessitating fractionation to achieve reasonable proteome coverage. Here, we present a simple yet effective peptide fractionation strategy that partitions a pooled TMT sample with a two-step elution using a strong anion-exchange (SAX) spin column prior to gradient-based basic pH reversed-phase (BPRP) fractionation...

Intact protein mass spectrometry (MS) coupled with liquid chromatography was applied to characterize the pharmacokinetics and stability profiles of therapeutic proteins. However, limitations from chromatography, including throughput and carryover, result in challenges with handling large sample numbers. Here, we combined intact protein MS with multiple front-end separations, including affinity capture, SampleStream, and high-field asymmetric waveform ion mobility spectrometry (FAIMS), to perform high-throughput and specific mass measurements of a multivalent antibody with one antigen-binding fragment (Fab) fused to an immunoglobulin G1 (IgG1) antibody...

Lipopolysaccharides (LPSs) are a hallmark virulence factor of Gram-negative bacteria. They are complex, structurally heterogeneous mixtures due to variations in number, type, and position of their simplest units: fatty acids and monosaccharides. Thus, LPS structural characterization by traditional mass spectrometry (MS) methods is challenging. Here, we describe the benefits of field asymmetric ion mobility spectrometry (FAIMS) for analysis of an intact R-type lipopolysaccharide complex mixture (lipooligosaccharide; LOS)...

The GET pathway is associated with post-translational delivery of tail-anchored (TA) proteins to the endoplasmic reticulum (ER) in yeast, as well as other eukaryotes. Moreover, dysfunction of the GET pathway has been associated with various pathological conditions (i.e., neurodegenerative disorders, cardiovascular ailments, and protein misfolding diseases). In this study, we used yeast deletion strains of Get complex members (specifically, Get1, Get2, Get3, Get4, and Get5) coupled with sample multiplexing-based quantitative mass spectrometry to profile protein abundance on a proteome-wide scale across the five individual deletion strains...

BACKGROUND: Quantification of drug-target binding is critical for confirming that drugs reach their intended protein targets, understanding the mechanism of action, and interpreting dose-response relationships. For covalent inhibitors, target engagement can be inferred by free target levels before and after treatment. Targeted mass spectrometry assays offer precise protein quantification in complex biological samples and have been routinely applied in pre-clinical studies to quantify target engagement in frozen tumor tissues for oncology drug development...

BACKGROUND: Food allergy affects the patient's quality of life (QoL) and leads to anxiety and depression. In addition to routine treatment, QoL evaluation should also be performed in patients with food allergies. The validated Food Allergy Quality of Life Questionnaire - Adult Form (FAQLQ-AF) and Food Allergy Independent Measure - Adult Form (FAIM-AF) have been well accepted and available in many languages. OBJECTIVE: Translate FAQLQ-AF and FAIM-AF into Thai and perform reliability and validity tests in Thai adult patients with food allergies...

BACKGROUND: Infection prevention and control (IPC) was a central component of the Democratic Republic of the Congo's COVID-19 response in 2020, aiming to prevent infections and ensure safe health service provision. OBJECTIVES: We aimed to assess the evolution of IPC capacity in 65 health facilities supported by Action Contre la Faim in three health zones in Kinshasa (Binza Meteo (BM), Binza Ozone (BO), and Gombe), investigate how triage and alert validation were implemented, and estimate how health service utilisation changed in these facilities (April-December 2020)...

INTRODUCTION: Cardiac arrhythmias are a major concern in patients with CHD. The purpose of this study was to evaluate the long-term outcomes in patients with CHD submitted to catheter ablation. MATERIALS AND METHODS: Observational retrospective study of patients with CHD referred for catheter ablation from January 2016 to December 2021 in a tertiary referral centre. Acute procedural endpoints and long-term outcomes were assessed. RESULTS: A total of 44 ablation procedures were performed in 36 CHD patients (55% male, mean age 43 ±3 years)...

AIM: Examining health-related quality of life (HRQoL) is important to improve patient care. In this study, we translate and evaluate the Finnish versions of the Food Allergy Specific Quality of Life Questionnaires (FAQLQs) from a Finnish perspective and undertake a detailed evaluation of the 10-question Parent Form Questionnaire (FAQLQ-PF10). METHODS: This validation study was performed to evaluate the Finnish versions of the FAQLQs. Validation was performed by analysing clinical characteristics, factor loadings and Cronbach's α reliability estimates...

Blood serum and plasma are arguably the most commonly analyzed clinical samples, with dozens of proteins serving as validated biomarkers for various human diseases. Top-down proteomics may provide additional insights into disease etiopathogenesis since this approach focuses on protein forms, or proteoforms, originally circulating in blood, potentially providing access to information about relevant post-translational modifications, truncations, single amino acid substitutions, and many other sources of protein variation...

High-field asymmetric waveform ion mobility spectrometry (FAIMS) separates glycopeptides in the gas phase prior to mass spectrometry (MS) analysis, thus offering the potential to analyze glycopeptides without prior enrichment. Several studies have demonstrated the ability of FAIMS to enhance glycopeptide detection but have primarily focused on N-glycosylation. Here, we evaluated FAIMS for O-glycoprotein and mucin-domain glycoprotein analysis using samples of varying complexity. We demonstrated that FAIMS was useful in increasingly complex samples as it allowed for the identification of more glycosylated species...

INTRODUCTION: It is critical to develop more inclusive Alzheimer's disease (AD) research protocols to ensure that historically excluded groups are included in preclinical research and have access to timely diagnosis and treatment. If validated in racialized groups, plasma AD biomarkers and measures of subtle cognitive dysfunction could provide avenues to expand diversity in preclinical AD research. We sought to evaluate the utility of two easily obtained, low-burden disease markers, plasma amyloid beta (Aβ)42/40, and intra-individual cognitive variability (IICV), to predict concurrent and longitudinal cognitive performance in a sample of Black adults...

Dual ionization sources combining an ultraviolet (UV) lamp source and a corona discharge (CD) source were first used as ionization sources for high-field asymmetric waveform ion mobility spectrometry (FAIMS) to switch ionization modes without changing hardware. The CD source was manufactured using a tungsten needle and a copper ring and its usability was verified. The UV source and the CD source were combined into the FAIMS sensor and multiple ionization modes were attempted by controlling their on-off status...

Here, we present a standardized, "off-the-shelf" proteomics pipeline working in a single 96-well plate to achieve deep coverage of cellular proteomes with high throughput and scalability. This integrated pipeline streamlines a fully automated sample preparation platform, a data-independent acquisition (DIA) coupled with high-field asymmetric waveform ion mobility spectrometer (FAIMS) interface, and an optimized library-free DIA database search strategy. Our systematic evaluation of FAIMS-DIA showing single compensation voltage (CV) at -35 V not only yields the deepest proteome coverage but also best correlates with DIA without FAIMS...

ADP-ribosylation (ADPr) is a post-translational modification that is best studied using mass spectrometry. Method developments that are permissive with low inputs or baseline levels of protein ribosylation represent the next frontier in the field. High-field asymmetric waveform ion mobility spectrometry (FAIMS) reduces peptide complexity in the gas phase, providing a means to achieve maximal ADPr peptide sequencing depth. We therefore investigated the extent to which FAIMS with or without traditional gas-phase fractionation-separation (GPS) can increase the number of ADPr peptides...

Middle-down proteomics (MDP) is an analytical approach in which protein samples are digested with proteases such as Glu-C to generate large peptides (>3 kDa) that are analyzed by mass spectrometry (MS). This method is useful for characterizing high-molecular-weight proteins that are difficult to detect by top-down proteomics (TDP), in which intact proteins are analyzed by MS. In this study, we applied GeLC-FAIMS-MS, a multidimensional separation workflow that combines gel-based prefractionation with LC-FAIMS MS, for deep MDP...

AIM: Specific questionnaires about food allergy and health-related quality of life (HRQoL) have been developed and validated in several languages, but not Finnish. We aimed to validate the Finnish Food Allergy Quality of Life Questionnaire-Parent Form (FAQLQ-PF) for children under age 13 years. METHODS: The original FAQLQ-PF and Food Allergy Independent Measure (FAIM) were translated into Finnish per World Health Organization guidelines and tested by 72 parents of children under age 13 years with suspected severe peanut or tree nut allergy who were recruited at Allergy Centre in Tampere University Hospital in Tampere, Finland...